The present invention relates, in general, to biopsy instruments and methods of taking biopsies and, more particularly, to a percutaneous biopsy instrument containing an element adapted to mark a biopsy specimen prior to harvesting.
The diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions, and other disorders has long been an area of intense investigation. Noninvasive methods for examining tissue are palpation, X-ray, MRI, CT, and ultrasound imaging. When the physician suspects that a tissue may contain cancerous cells, a biopsy may be done either in an open procedure or in a percutaneous procedure.
For an open procedure, a scalpel is used by the surgeon to create a large incision in the tissue in order to provide direct viewing and access to the tissue mass of interest. Removal of the entire mass (excisional biopsy) or a part of the mass (incisional biopsy) is done. The excised mass of tissue is examined by the surgeon and then by a pathologist using more precise means to determine if all of the cancerous tissue has been excised. Through direct visualization and palpation the surgeon inspects the excised tissue mass to determine if cancer may exist at the edges of the excised mass. This is followed by the pathologist examining the mass using various techniques to determine if cancer cells are near the edge. To aid the pathologist the surgeon typically identifies the in situ orientation of the mass. This is done by inserting sutures at predetermined locations around the edges of the mass or by marking the edges of the mass with a stain, commonly India ink. If the pathologist then determines that there are cancer cells near one of the edges of the mass the pathologist can direct the surgeon to remove additional tissue from the patient in the area corresponding to the locators marked on the original tissue specimen.
For a percutaneous biopsy, a needle-like instrument is used. An example of a percutaneous biopsy device is the Mammotome(trademark) biopsy system available from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. Mammotome works through a very small incision to access the tissue mass of interest and to obtain a tissue sample for examination and analysis. Multiple tissue specimens can be removed through a single insertion. The Mammotome biopsy probe typically is rotated about its longitudinal axis at predetermined increments to a new position as each specimen is harvested. Using this technique multiple adjacent tissue samples can be removed. Multiple 360 degree revolutions of the probe may be necessary to remove all of the desired tissue.
The advantages of the percutaneous method as compared to the open method are significant: less recovery time for the patient, less pain, less surgical time, lower cost, less risk of injury to adjacent bodily tissues such as nerves, and less disfigurement of the patient""s anatomy. However, since the tissue mass is removed in multiple pieces, reconstruction of the mass from the harvested pieces is challenging. With great care the clinician can identify and document the order of each specimen""s removal. And, because each tissue specimen is cylindrical in geometry and the distal to proximal end orientation is maintained during the specimen harvesting procedure, the clinician can maintain the distal to proximal end orientation of the specimens during post biopsy analysis. What the clinician does not know, however, is the radial orientation of the cylindrical biopsy specimen as it was prior to being harvested. Once the specimen is severed and captured by Mammotome""s rotating cutter, in situ radial orientation is lost. Lack of this information makes it difficult to accurately reconstruct the tissue mass to determine if all cancerous cells have been harvested. Without radial orientation information, especially on the last biopsy specimens to be taken since they typically represent the outer perimeter of the entire tissue mass harvested, it""s difficult for the pathologist to direct the clinician back to a specific area at the biopsy site if additional tissue is needed.
Radial orientation of other biopsy devices has also been a problem. In the prior art, PCT application number WO0012010 to Sirimanne et al describes a percutaneous tissue biopsy device incorporating a rotating wire which produces a helical cut. A tissue mass can be removed through a comparatively small opening and readily reconstructed. Unfortunately, however, the in situ orientation of the tissue mass is lost once removed from the patient. U.S. Pat. No. 6,036,698 to Fawzi et al describes a percutaneous tissue biopsy device using an expandable ring cutter. A relatively large tissue specimen can be removed through a comparatively small device. Again no means is described in this invention for marking the in situ orientation of the tissue specimen and, therefor, orientation is lost upon removal from the patient. U.S. Pat. No. 5,578,030 to Levin describes a biopsy needle with a cauterization feature. In this invention tissue specimens are harvested through a stylet contained within a biopsy needle. Once the specimen is taken, the biopsy needle is energized to cauterize the wound caused by the taking of the tissue specimen. This invention features a means for insulating the excised tissue specimen from the cauterizing heat. No means is described for marking in situ orientation of the specimen. Similarly, U.S. Pat. No. 5,295,990 to Levin describes a tissue biopsy device with pivoting cutting jaws. Once the tissue specimen is severed, by closing the cutting jaws, the jaws are energized with electric current to cauterize tissue surrounding the jaws. An insulating material covers the inside of the jaws where the tissue specimen resides to protect the specimen from the cauterization heat. Again, no means are described to mark the specimen to identify orientation.
What is needed is a percutaneous biopsy instrument incorporating an element for marking the orientation of each specimen in situ, prior to harvesting and examination.
A biopsy probe for the collection of at least one soft tissue sample from a surgical patient. The biopsy probe has a handle, having a distal end and a proximal end, for holding the probe. The probe further includes an elongated needle, located at the distal end of the handle. The needle has a sharpened distal end for piercing tissue and a bowl for receiving a tissue mass. The probe has a cutter for severing the tissue mass received in the bowl, and at least one tissue marker element to apply a mark to the exterior of the tissue so the radial orientation of the tissue can later be determined.